Spray nozzle



July 21, 1953 D. J. PEEPS SPRAY NOZZLE Filed Oct. 19. 1950 IIIIII/ 4 4 aZinnentor:

1702mm 12 321 5. Bu 4 pe attorney Patented July 21, 1 953 Donald- J.Peeps, Toledo, Ohio, assign'o'r' to The. .De Vilbiss Company,Toledo,..Qhio.; a corporation of Ohio Application October '19, 1950;s'1eriai-No. 190,952

.7 Claims; (01. zest-140i)? This-invention relates to spray nozzlesutilizing compressed airfor atomization and particularly to such nozzlesin which a plurality of supplemental air jets are directed toward thedischarged stream of spray material to further atomize it and to form itinto a desired pattern.

In the conventional-spray nozzle of this type, as used for spray coatingfurniture, refrigerator housings, automobile bodies and the like,there'is. an annular air outlet opening around a circular spray materialoutlet. The purpose of the air from this annular opening is the primaryatom- Italso provides a proization' of the material. tective sheatharound the material stream which tends to prevent an uncontrolleddispersion of the atomized material by the impingement of supplementalair jets. Prior to beingsubjected to the action of the supplemental airjets the atomized material stream has a forwardly flaring conical form.

It has long been customary'to shape the spray discharge stream into amore serviceable fanpatt'ern'by projecting against opposite sides of thestream forwardly converging air jets. Various other auxiliary air jetsof smaller size, and from ports closer to the center orifice than thoseof the main flattening jets, are used quite generally for improving theatomization, modifying the spray discharge pattern, and assisting inkeeping the spray nozzle-clean. The arrangement. of these supplementaljets in spray nozzles commercially available haveuntil recently givensatisfactory service with coating materials commonly employed. v

However, the ever increasing rate of consumer demands hasmade improvedmanufacturingprocedures mandatory. To meet the urgent'need for greaterproduction and lower costs in finishing operations manufacturers are nowadopting high-.- er viscosity, heavier bodied materials. These reducethe number of coats required to obtain the.

film thickness desired. It is more difficult to atomize these moreviscous materials and, if the. material i's-not well broken up, theresulting film' surface is rough and more time is consumed in sandingand polishing. This additional labor may reduce or nullify the savingsattained from the.

application of a fewer number of coats.

The spray nozzle of this invention meets the challenge of these advancedrequirements by pro.- viding extremely high atomization with bothlacquers and synthetic enamels in a viscosity range of 17 to 32 secondson a No. 4 Ford cup. At the same time the spraypattern delivered by thisspraynozzle is a' fan of exceptional spread, being approximately l5/g-=incheswide at 6% inches from the surfaceand isaccordi'nglywelladapted terial is evenly distributed throughout the fan for coatinglargesurfaces at a high speed. 'A minimum of lapping ofithe spraystrokes-is necessary as the fan pattern isstraight sided except for wellformed tapers at the ends, and as the spray mapat'tern. This; outstandinimprovement in performance is derived" principally from the noveldisposition of supplementalair jetports on the sides of the centerorifice; SO -abOutthe axis from the-location of the main flattening jetports, and supplementarily from anex-act' positioning of the spraymaterial tipinrelation to the spray nozzle, as hereafter; more fullydescribed and as illustrated in the accompanying drawings in which:

Figure 'lis a front view.- ofa spraynozzle em bodying my=invention;

Figure-2 is a central vertical section taken on 'line 2 z of Figure 1;

"Figure 3 is-a central horizontal section taken on; line 3-3 of Figure Iand Figure 4 is a perspective view of the front and side ofthe'embodiment.

Referring to the drawing, my "invention is shown as applied to a spraynozzle I with a central orifice'2 Intothis orifice'extends aspraymaterial tip-3 as shownin Figure 2. A needle valve 4-is the conventionalmember for controlling the discharge ofsp'ray material from' tip 3'.

This invention incorporates the discovery that, with spray nozzles ofhigh capacities and fine atomization, cleanliness of the spray nozzlemay be better assured by spacing theend of the spray material tiprearwardly of the spray nozzle frontal faceapproximately .003 inch. Thegeneral practwo has been to have the end. of the material tip flush:withv thespray nozzle surface. A variation from. this practice; hasbeen-to. have the material tip extend beyond thesurrounding'spray nozzlesurface. to increasethe. aspiratingeffect of the air flow. upon thematerial.

The primary atomizing air travels through space 5 surrounding tip. 3and. issues; from the.

spray nozzlethrough theannular opening, formed between. the forwardendof'tip3' andthe periphcry of orifice 2. This air. provides theinitial atomization of the discharged spraymaterial and in conjunctiontherewith travels forwardly in a gradually expanding conical stream.

From-horns-G and F, pairs of converging fiattening jets are emitted fromports 8, 9', H! and H against theatomized"material stream to shape itintoits final fan pattern.

Between each horn and the center orifice are two ports I2 and I3. Theseemit clean up air jets in paths parallel or slightly inclined toward theaxis of the center orifice. These jets aid in keeping the face of thespray nozzle clean and tend to shield the spray material stream from apiercing impingement by the main flattening jets from the horns.Experience has shown that a single jet of this type in front of eachhorn may give as satisfactory results as the double jets of thisspecific embodiment.

On the sides of the center orifice, 90 about its axis from the locationof the horns and the clean up jet ports, are oppositely placed sets ofthree ports M and [5. These ports are disposed in a well-forminginverted frustro-conical surface flaring outwardly from theface portionof the spray nozzle surrounding the center orifice. The axes of theports areperpendicular to the conical surface, or, as possibly morecorrectly defined, are perpendicular to planes tangent to the conicalsurface at points of intersection of the axes with the conical surface.The frustro-conical surface is on the inner side of a ridge which isnon-continuous on the sides adjacent the horns B and l. The two segmentsl6 and I! of the ridge form horns of miniature size compared to thehorns 6 and i, but which are proportionately wider circumferentially ofthe nozzle. In regard to both pairs of horns the inwardly facingsurfaces in which the horn air ports are located are conical in contourand the port axes are perpendicular to the conical surfaces.

Due to the raised location of the ports l4 and I5 they are brought intocloser proximity to the axis of the central orifice. This feature inassociation with the symmetrical encircling relation of the port surfacearea to said axis results in a special concentration of the power of thejets emitted from these portsupon the central stream of material andair.

Each set of three ports is positioned to project three air jets alongconverging axe meeting at a common point on the axis of the centerorifice. The power and action of these merging jets so agitate and formthe primarily atomized stream of spray material that, with thesubsequent impingement of the main flattening jets from the horn ports,8, 9, i and II, the stream of material becomes thoroughly atomized andevenly distributed throughout an exceptionally wide fan pattern.

My copending application Ser. No. 184,538, filed September 13, 1950,similarly entitledSpray Nozzle, relates to a specific form of the basicfeature of striking the central stream near its source on opposite sideswitha plurality of non merging jets. Instead of having the jets directedalong converging paths as in this application the jets of this copendingapplication are directed along parallel paths.

In one form of my invention with which typically excellent results maybe obtained, the more forward port (8 and 40) in each horn is .052 of aninch in diameter and is directed at an angle of 65 toward the axis ofthe center stream; and the more rearward port (9 and H) of each horn hasa diameter of .070 of an inch and is directed at an angle of 58 towardthe center stream axis.

The inner clean up jets in this preferred form issue from ports I3 whichare .024 of an inch in diameter and direct air jets toward the centeraxis at an angle of while the outer clean up jet ports 12 are .0225 ofan inch in diameter and 4 their jet paths are angled at 10 to the streamaxis.

The atomizing jets emitted from the sets [4 and 15 of three ports oneach side, 90 about the axis from the horns, strike the center axis atan angle of The centers of the ports lie in an arc with a radius of .125of aninch from the axis of the center orifice. The individual ports oneach side are .054 inch apart from center to center, and each is .025 ofan inch in diameter.

In another form of my invention with which very good results may besecured the more forward horn 'port is '.070 of an inch in diameter anddirected in a path angled toward the center axis at 65, while the morerearward horn port is .0685 of an inch in diameter and is angled at Thisis at variance with the horn port arrangement of the first formdescribed in that the more forward port is larger instead of smallerthan the more rearward port and the angles to the center axis of theemitted jets difier. It may be noted that the smaller of the morerearward jets meets the central stream at a slightly more direct angle.This is inclined to compensate for the reduction in size.

The three sets of atomizing ports (14 and i5) at opposite sides of thecenter orifice in the second form all direct air jets along paths angledat 30to the axis of the center orifice, the

two outer ports of each set being .026 of an inch in diameter andtheinner one .038 of an inch.

They are all .107 of an inch from the center oricific embodiment but maybe utilized with various sizes, positions, and angularity ofsupplemental air jets. 7

Accordingly it is not desired to be limited to the exact disclosuresherein set forth, but rather to the scope of the appended claims.

What I claim is:

l. A spray nozzle of the type having a center orifice for the dischargeof an expanding conical stream of material and air, primary port meansfor-impinging atomizing air jets against opposite sides of the streamand secondary port means in a plane diametric of the axis of the centerorifice and ninety degrees about the axis from the primary port meansfor impinging air jets against opposite sides of the stream, subsequentto the impingement of the atomizing air jets, to form the stream intoits final fan shape, said spray nozzle characterized by having saidprimary port means include ,a separate distinct setof closely adjacentcircumferentially spaced ports on each of opposite sides of the centeror-i fice with said ports formed and positioned to dischargev air jetsagainst opposite sides of the, stream along paths angled relative toeach other with each jet impinging the stream at an angle to the axisthereof of at least thirty degrees and at a point circumferentiallyspaced from the point of impingement of an adjacent jet, whereby thestream is indented at a plurality of points on each side and isflattened and spread laterally in the diametric plane in which thesecondary port means are positioned and; on opposite v sides of whichthe sets of primary port means are positioned. 1

2. A spray nozzle according to claim 1 in which the port means for theatomizing jets on each side of the center orifice lie Within a quadrantof a circle centered on the axis of the center orifice. v

3. A spray nozzle according to claim 1 in which all the atomizing jetsare directed. toward the same point on the axis of the center orifice.

4. .A spray nozzle according to claim 1 in which the ports for theatomizing. air jets are equidistant from the center orifice.

, 5. In a spray nozzle of the type having a center orifice for thedischarge of an expanding conical stream of material and air, a pair ofconventional horns on diametrically opposite, sides of the centerorifice projecting forwardly thereof from the peripheral area of thespray nozzle and port means in the horns for discharging air jetsagainst the stream 'to shape it into its final fan form, the combinationwith said conventional horns of a second pair of horns on diametricallyopposite sides of the center orifice 90 about the center orifice fromthe position of the conventional horns, the second pair ofhornsprojecting forwardly a lesser distance and being closer to the centerorifice than the conventional horns, and port means' in the second pairof horns di recting a plurality of atomizing jets of air againstopposite sides of the stream prior to the discharge there against of theair jets from the conventional horns. v

6. A spray nozzle according to claim 5 in which the surfaces of eachpair of horns in which the ports are located follow the outer contour ofa forwardly'expanding cone concentric with the central orifice; p

7. Aspray nozzleaccording to claim 6 in which the axis of each horn portis perpendicular to the conical surface in which it is located.

DONALD J. PEEPS.

References Cited'in the file of this patent UNITED STATES PATENTS NumberName Date 2,019,941 Tracy Nov. 5, 1935 2,029,423 jGustafson Feb. 4, 19362,269,057 Jenkins Jan. 6, 1942 Jenkins Nov. 24, 1942

